In a conventional plasma display panel (hereinafter referred to as "PDP") of the pulse memory type, in addition to display discharge cells, auxiliary discharge cells are needed for rapid and accurate display within a short time.
An example of the above mentioned conventional PDP is disclosed in Japanese Patent Publication No. 60-193235, which is shown as a partially sectional view in FIG. 1, and a cross sectional view in FIG. 2. In the drawings, display cathode array 11 is formed on rear glass plate 10, and latticed barrier ribs 15 are formed thereon to form discharge cell spaces. Meanwhile, display anode array 13 and auxiliary anode array 14 are formed on the inner surface of a face plate 20. The display and auxiliary anode arrays 13 and 14 are disposed at the respective center between barrier ribs 15 so as to face and intersect with the corresponding display cathodes of the display cathode array 11. Then, discharging gas is injected into the panel under a certain vacuum state, and the peripherals of plates 10 and 20 are sealed together as shown in FIG. 2. Numeral 16 indicates a light cutoff layer for maintaining the brightness of a dark level at a sufficiently low value by blocking light given off by the auxiliary discharge.
However, in the conventional PDP constructed as described above, since all the display anodes are formed on the face plate, the effective light emission area is decreased which results in a lower brightness. In particular, since the plurality of display cells are simultaneously turned on by the memory function of the pulse memory driving system, a large amount of current flows within the display anodes, and thus there may be a problem that all the display cells corresponding to the display anodes are simultaneously discharged in the extreme case. Therefore, the display anodes are required to be formed relatively wide for supplying large currents. But in this case, because the display anodes are arranged on the inner surface of the face plate, the wide display anodes block the discharged light generated from the display cells, thereby even further reducing the effective light emission area. As a result, the brightness becomes further deteriorated.
Moreover, by the fact that the discharge initiation voltage depends on the distance between each display anode and cathode, the distance between each anode and cathode should be maintained within a predetermined range for achieving a stable memory function without erroneous operation. However, the larger size of the panel causes a greater variation of the distance between the display anodes and the cathode array, and thus it is impossible to obtain overall stable memory operation.
Furthermore, because all the paths of charged gas particles from the auxiliary discharge space to the display discharge space are formed at the upper portion of the discharge space, it causes a problem that the light emitted by the auxiliary discharge leaks into the discharge cell region, thereby decreasing the contrast ratio.